Generering av tilfeldige tall er et vanlig krav i mange programmeringsapplikasjoner, og C++ gir flere måter å generere tilfeldige tall innenfor et gitt område. I denne artikkelen vil vi utforske ulike metoder for å generere tilfeldige tall mellom 1 og 10 i C++.
Metode 1:
Bruker rand() funksjonen:
En av de enkleste metodene for å generere et tilfeldig tall mellom 1 og 10 i C++ er rand() funksjon. Denne funksjonen er definert i header-fil og genererer et tilfeldig heltall innenfor et område på 0 til RAND_MAX . Verdien av RAND_MAX er implementeringsavhengig og kan variere fra kompilator til kompilator.
Eksempel:
La oss ta et eksempel for å generere et tilfeldig tall mellom 1 og 10 ved å bruke rand()-funksjonen, vi kan bruke følgende kode:
#include #include #include using namespace std; int main() { srand(time(0)); cout<< 'Random number between 1 and 10 is: '<<endl; for(int i="0;i<10;i++)" cout << (rand() % 10) + 1<<' '; return 0; } < pre> <p> <strong>Output</strong> </p> <pre> Random number between 1 and 10 is: 4 5 7 10 7 5 1 7 10 2 </pre> <p>In this code, we have included the <strong> <em></em> </strong> and <strong> <em></em> </strong> header files. The <strong> <em>srand()</em> </strong> function is used to initialize the random number generator with the current time as the seed. It ensures that every time the program is run, a new sequence of random numbers is generated.</p> <p>The <strong> <em>rand()</em> </strong> function is used to generate a random integer between 0 and <strong> <em>RAND_MAX</em> </strong> . To limit the range between 1 and 10, we take the remainder of this number when divided by 10 and add 1 to it.</p> <h3>Method 2:</h3> <p> <strong>Using C++11 random library</strong> </p> <p>The <strong> <em>C++11</em> </strong> standard introduced a new library called <strong> <em></em> </strong> that provides a better way to generate random numbers. This library provides several random number generation engines and distributions that can generate random numbers with a uniform distribution.</p> <p> <strong>Example:</strong> </p> <p>Let's take an example to generate a random number between 1 and 10 using the <strong> <em></em> </strong> library, we can use the following code:</p> <pre> #include #include using namespace std; int main() { random_device rand; mt19937 gen(rand()); uniform_int_distributiondis(1, 10); int random_number = dis(gen); cout<< 'Random number between 1 and 10 is: ' <<random_number<<endl; return 0; } < pre> <p>In this code, we have included the <strong> <em></em> </strong> header file. The <strong> <em>random_device</em> </strong> class is used to obtain a seed value for the random number generator. The <strong> <em>mt19937</em> </strong> class is a random number generation engine that produces random numbers with a uniform distribution. The <strong> <em>uniform_int_distribution</em> </strong> class is used to generate random integers within a given range.</p> <p>By default, the <strong> <em>mt19937</em> </strong> engine uses a seed value of <strong> <em>5489</em> </strong> , which can be changed using the <strong> <em>seed()</em> </strong> method. However, it is recommended to use a <strong> <em>random_device</em> </strong> to obtain a seed value for better randomness.</p> <p>The <strong> <em>uniform_int_distribution</em> </strong> class generates random integers with a uniform distribution within a given range. In this code, we have specified the range as <strong> <em>1</em> </strong> to <strong> <em>10</em> </strong> using the constructor.</p> <p>This method provides better randomness and a uniform distribution of generated numbers compared to the <strong> <em>rand()</em> </strong> function. However, it is slower and more complex to implement.</p> <h3>Method 3:</h3> <p> <strong>Using modulo operator with time():</strong> </p> <p>Another method to generate a random number between 1 and 10 is the <strong> <em>modulo operator</em> </strong> with the current time as a seed value. This method is similar to the first method using <strong> <em>rand()</em> </strong> function, but it uses a more random seed value and provides better randomness.</p> <p> <strong>Example:</strong> </p> <p>Let's take an example to generate a random number between 1 and 10 using the modulo operator with <strong> <em>time()</em> </strong> , we can use the following code:</p> <pre> #include #include using namespace std; int main() { srand(time(0)); cout<< 'Random number between 1 and 10 is: ' <<endl; for(int i="0;i<10;i++)" cout << (rand() % 10) + 1<<' '; return 0; } < pre> <p> <strong>Output</strong> </p> <pre> Random number between 1 and 10 is: 6 6 3 6 10 10 1 7 6 4 </pre> <p>In this code, we have used the <strong> <em>time()</em> </strong> function to obtain the current time as a seed value for the <strong> <em>srand()</em> </strong> function. The <strong> <em>srand()</em> </strong> function is used to initialize the random number generator. The <strong> <em>rand()</em> </strong> function generates a random integer between 0 and <strong> <em>RAND_MAX</em> </strong> , which is then limited to a range between 1 and 10 using the <strong> <em>modulo operator</em> </strong> and adding 1 to it.</p> <h2>Conclusion:</h2> <p>In conclusion, there are several methods to generate random numbers between 1 and 10 in C++. The choice of method depends on the requirements of the application, such as <strong> <em>speed, randomness</em> </strong> , and <strong> <em>uniformity</em> </strong> of generated numbers. While the <strong> <em>rand()</em> </strong> function is the simplest and easiest to implement, it may not provide good randomness and uniformity. The <strong> <em></em> </strong> library provides a better way to generate random numbers with a uniform distribution, but it is slower and more complex to implement. The <strong> <em>XORShift</em> </strong> algorithm provides good <strong> <em>randomness</em> </strong> and <strong> <em>uniformity</em> </strong> , but it is more complex to implement and may not be as fast as the <strong> <em>rand()</em> </strong> function.</p> <hr></endl;></pre></random_number<<endl;></pre></endl;> I denne koden har vi inkludert og header-filer. De srand() funksjonen brukes til å initialisere tilfeldig tallgenerator med gjeldende tid som frø. Det sikrer at hver gang programmet kjøres, genereres en ny sekvens med tilfeldige tall.
De rand() funksjonen brukes til å generere et tilfeldig heltall mellom 0 og RAND_MAX . For å begrense området mellom 1 og 10, tar vi resten av dette tallet når det deles på 10 og legger til 1 til det.
Metode 2:
Bruker C++11 tilfeldig bibliotek
De C++11 standard introduserte et nytt bibliotek kalt som gir en bedre måte å generere tilfeldige tall på. Dette biblioteket tilbyr flere tilfeldige tallgenereringsmotorer og distribusjoner som kan generere tilfeldige tall med en enhetlig fordeling.
Eksempel:
La oss ta et eksempel for å generere et tilfeldig tall mellom 1 og 10 ved å bruke bibliotek, kan vi bruke følgende kode:
#include #include using namespace std; int main() { random_device rand; mt19937 gen(rand()); uniform_int_distributiondis(1, 10); int random_number = dis(gen); cout<< 'Random number between 1 and 10 is: ' <<random_number<<endl; return 0; } < pre> <p>In this code, we have included the <strong> <em></em> </strong> header file. The <strong> <em>random_device</em> </strong> class is used to obtain a seed value for the random number generator. The <strong> <em>mt19937</em> </strong> class is a random number generation engine that produces random numbers with a uniform distribution. The <strong> <em>uniform_int_distribution</em> </strong> class is used to generate random integers within a given range.</p> <p>By default, the <strong> <em>mt19937</em> </strong> engine uses a seed value of <strong> <em>5489</em> </strong> , which can be changed using the <strong> <em>seed()</em> </strong> method. However, it is recommended to use a <strong> <em>random_device</em> </strong> to obtain a seed value for better randomness.</p> <p>The <strong> <em>uniform_int_distribution</em> </strong> class generates random integers with a uniform distribution within a given range. In this code, we have specified the range as <strong> <em>1</em> </strong> to <strong> <em>10</em> </strong> using the constructor.</p> <p>This method provides better randomness and a uniform distribution of generated numbers compared to the <strong> <em>rand()</em> </strong> function. However, it is slower and more complex to implement.</p> <h3>Method 3:</h3> <p> <strong>Using modulo operator with time():</strong> </p> <p>Another method to generate a random number between 1 and 10 is the <strong> <em>modulo operator</em> </strong> with the current time as a seed value. This method is similar to the first method using <strong> <em>rand()</em> </strong> function, but it uses a more random seed value and provides better randomness.</p> <p> <strong>Example:</strong> </p> <p>Let's take an example to generate a random number between 1 and 10 using the modulo operator with <strong> <em>time()</em> </strong> , we can use the following code:</p> <pre> #include #include using namespace std; int main() { srand(time(0)); cout<< 'Random number between 1 and 10 is: ' <<endl; for(int i="0;i<10;i++)" cout << (rand() % 10) + 1<<\' \'; return 0; } < pre> <p> <strong>Output</strong> </p> <pre> Random number between 1 and 10 is: 6 6 3 6 10 10 1 7 6 4 </pre> <p>In this code, we have used the <strong> <em>time()</em> </strong> function to obtain the current time as a seed value for the <strong> <em>srand()</em> </strong> function. The <strong> <em>srand()</em> </strong> function is used to initialize the random number generator. The <strong> <em>rand()</em> </strong> function generates a random integer between 0 and <strong> <em>RAND_MAX</em> </strong> , which is then limited to a range between 1 and 10 using the <strong> <em>modulo operator</em> </strong> and adding 1 to it.</p> <h2>Conclusion:</h2> <p>In conclusion, there are several methods to generate random numbers between 1 and 10 in C++. The choice of method depends on the requirements of the application, such as <strong> <em>speed, randomness</em> </strong> , and <strong> <em>uniformity</em> </strong> of generated numbers. While the <strong> <em>rand()</em> </strong> function is the simplest and easiest to implement, it may not provide good randomness and uniformity. The <strong> <em></em> </strong> library provides a better way to generate random numbers with a uniform distribution, but it is slower and more complex to implement. The <strong> <em>XORShift</em> </strong> algorithm provides good <strong> <em>randomness</em> </strong> and <strong> <em>uniformity</em> </strong> , but it is more complex to implement and may not be as fast as the <strong> <em>rand()</em> </strong> function.</p> <hr></endl;></pre></random_number<<endl;> I denne koden har vi brukt tid() funksjon for å få gjeldende tid som en frøverdi for srand() funksjon. De srand() funksjonen brukes til å initialisere tilfeldig tallgeneratoren. De rand() funksjonen genererer et tilfeldig heltall mellom 0 og RAND_MAX , som da begrenses til et område mellom 1 og 10 ved å bruke operatørmodul og legger til 1 til den.
Konklusjon:
Avslutningsvis er det flere metoder for å generere tilfeldige tall mellom 1 og 10 i C++. Valg av metode avhenger av kravene til søknaden, som f.eks hastighet, tilfeldighet , og ensartethet av genererte tall. Mens rand() funksjonen er den enkleste og enkleste å implementere, den gir kanskje ikke god tilfeldighet og ensartethet. De biblioteket gir en bedre måte å generere tilfeldige tall med en enhetlig fordeling, men det er tregere og mer komplekst å implementere. De XORShift algoritme gir god tilfeldighet og ensartethet , men det er mer komplekst å implementere og er kanskje ikke så raskt som rand() funksjon.